MU Extension MU Extension       University of Missouri    ●    Columbia    ●    Kansas City       Missouri S&T     ●    St. Louis - Food Safety


Feature Articles

Food safety after a power outage

Adapted by Jessica Kovarik, RD, LD, former Extension Associate, from materials written by Janet Hackert, Nutrition and Health Education Specialist and Tammy Roberts, Nutrition and Health Education Specialist, University of Missouri Extension


When the power goes out, whether it’s the result of a storm or just by accident, it’s important to know which foods are safe to eat and which are not. Here are some tips on how to safely handle food after an outage.


Once the electricity goes off, a full freezer will hold temperatures for 48 hours. A half-full freezer will hold a freezing temperature for 24 hours. You can extend this time by filling the freezer with newspaper or blankets. A refrigerator can only maintain a safe temperature for around four hours. It is important to only open the freezer or refrigerators doors when absolutely necessary.


When the freezer has been off, the basic guide in determining a food’s safety is whether or not it still contains ice crystals. If it does, the food (except seafood) should be refrozen as quickly as possible. It is a good idea to mark each package with an “X” or label as “Refrozen” to indicate that these items should be eaten first and as soon as possible.


If any food has thawed and there are no ice crystals on it, it should be thrown away. If you notice blood from once-frozen meat on neighboring packages or in the bottom of the freezer, advanced thawing has certainly occurred and those foods should be thrown out.


It is also OK to re-freeze foods if the thermometer in the freezer reads 40 degrees Fahrenheit or less. Once food has been above 40 degrees Fahrenheit for more than two hours, it should be discarded. This is also true if the power comes back on without realizing power was restored.


Refrigerator temperature should be kept at 40 degrees Fahrenheit or colder.


If the power is out for 2 hours or more, perishable foods in the fridge should be discarded. These foods include:

  • Meats of any sort, including fresh meats, lunch meats, open containers/cans of meat or leftovers with meat
  • Eggs, whether raw, hard-cooked or in a casserole or other dishes
  • Dairy products, specifically liquid and creamy dairy products like milk, cream cheese, cottage cheese, sour cream and yogurt
  • Soft cheeses including Brie, Colby, Monterey Jack, ricotta, mozzarella and Muenster
  • Shredded cheese should also be discarded
  • Opened, creamy salad dressings
  • Stews, casseroles, soups and other leftover cooked foods like vegetables, tomato sauce, cookie dough


Toss condiments, such as opened jars of mayonnaise, tartar sauce and horseradish, if they were above 50 degrees F for more than 8 hours.


The following items can be kept at room temperature for a few days:

  • Peanut butter
  • Butter or margarine
  • Fresh or dried fruits
  • Open/canned fruit and fruit juices
  • Jelly
  • Relish
  • Catsup
  • Taco sauce
  • Barbecue sauce
  • Pickles
  • Opened vinegar-based dressing
  • Raw vegetables
  • Baked goods
  • Hard cheeses like cheddar, Swiss, parmesan, Romano and provolone
  • Processed cheeses


The USDA Food Safety and Inspection Service website has a chart on specific foods and recommendations on salvaging or discarding after a power outage. This chart and additional information can be found in their article Keeping Food Safe During an Emergency.


You cannot smell or taste harmful bacteria. If you are not sure how long a food has been above 40 degrees or if you are feeling uncertain about the item, remember the rule “when in doubt, throw it out!”


University of Missouri logo links to

Site Administrator:
Copyright  ADA  Equal Opportunity

MissouriFamilies is produced by the College of Human Environmental Sciences,
Extension Division, University of Missouri

Last update: Monday, April 07, 2014